Christian's Blog: Oktober 2010

Wer die Virtualisierungsplatform Virtualbox nutzt, der möchte eine dauerhaft laufende Virtuelle Maschine auch sichern. Genau für diesen Zweck habe ich mir ein Backupskript geschrieben.

Wie funktioniert es:
Es sucht nach den gehosteten virtuellen Maschinen fährt diese gegebenenfalls herunter, so dass diese sich in einem gesicherten Zustand befinden. Danach werden die virtuellen Maschinen eine nach der anderen an einen konfigurierbaren Ort gesichert. Dazu werden die von Virtualbox zur Verfügung stehenden Tools verwendet. Nachdem der Backupprozess abgeschlossen ist, wird diese wieder gestartet. Es wird sich auch gemerkt, welche VM vor dem Backup gestartet war, nur diese wird dann auch wieder gebootet.

#!/bin/bash
#####################################################################
#Export, backup script for virtualbox.
#Before running in all vms the ACPI funtion has to be working fine.
#
#Copyright by Christian Wack (2010)
#mail: wackchristian@googlemail.com
######################################################################

#variables
LOGFILE="/home/virtualbox/virtualbox-backup.log"
vmIsRunning=0
vmName="UbuntuServer"
maxRetries="20"
sleeptime=7
backupFolder="/media/Backup/Backups/`date +"%d.%m.%Y"`/VMs/"
vmRunningBeforeBackup=0
vmList=""
declare -a vmNamesArray

#Logging method. Writes the given string out into logfile.
#@param the string to log
log(){
   echo $* >>$LOGFILE
}

log ""
log "START"
log "Starting Backup Process at `date`"

log "Creating directories for backup $backupFolder"
mkdir -p $backupFolder 
log "Backup Folders created"

#Checks if the given VM is running
#@param the name of the vm
isRunning(){
 if [ `VBoxManage list runningvms|grep \"${1}\"|wc -l` -eq 0 ] ;  
      then log "Not Running VM ${1}"
      vmIsRunning=0
 else log "Is running VM ${1}"
      vmIsRunning=1
 fi
}

#Lists all vm to backup them
findVMs(){
 log "Listing VMs"
 vmNames=`VBoxManage list vms | grep \"*\" | sed 's/$" $.*/\1/' | sed 's/.*/\1/' | sed 's/.$.*$./\1/' | sed -e 's/.$//' | sed -n '1h;2,$H;${g;s/\n/ /g;p}'`
 log "VM Count: ${#vmNames[@]}"
 vmNamesArray=( $vmNames )
 log "VMs found: $vmNamesArray"
}

#Method handling the shutdown of the given vm.
#Waiting for shutting down via ACPI. If timeout the vm will be controlled by poweroff.
#@param the name of the vm
shutDownVM(){
   log "Shutting down VM $1"
   VBoxManage controlvm $1 acpipowerbutton
   I=1                              
   while [ $I -le $maxRetries ] ;   
   do
      log $I                       
      I=`expr $I + 1`              
      log "The vm is still running"
      sleep $sleeptime
      isRunning $1   
      if [ $vmIsRunning -eq 0 ] ;
        then break
      fi
   done
   #@FIXME Temporarly set always true, because the DEV-VM could not be exported somethimes. It is locked yet.
   #if [ $vmIsRunning -eq 1 ] ;
   if [ 1 -eq 1 ]
     then VBoxManage controlvm $1 poweroff
     sleep $sleeptime
     isRunning $1
     log "Had to poweroff the vm, the vm is runing=$vmIsRunning"
   fi
   #wait one more time for unlocking safe
   sleep $sleeptime
}

#Exports the halted vm to the backupfolder as ovf file and vmdk file.
#@param the name of the vm
backupVM() {
  log "Begin backuppping the VM $1"
  VBoxManage export $1 -o $backupFolder$1.ovf
  log "Backuping of VM $1 finished"
}

#Starts the vm by pushing the power button.
#@param the name of the vm
startVM() {
  log "Starting VM $1"
  VBoxManage startvm $1
  log "VM has been started"
}

#Controls the workflow for backup.
#First if vm is running it will be shutted down.
#Second the vm will be exported (backuped).
#Third the vm will be started again, if it was running before backupping
#@param the name of the vm
vmWorkflow(){
   log "Checking if the VM $1 is running"
   isRunning $1
   log "The VM $1 is running="$vmIsRunning
   
   if [ $vmIsRunning -eq 1 ] ;
     then shutDownVM $1
     vmRunningBeforeBackup=1
     else log "VM is not running $vmIsRunning"
     vmRunningBeforeBackup=0
   fi

backupVM $1
   if [ $vmRunningBeforeBackup -eq 1 ] ;
     then log "Starting VM $1, because VM was also running before backup"
     startVM $1
     else log "Starting of VM $1 skipped, because VM was not running before backup"
   fi
}

#The main method.
#Here everything begins.
main(){
 findVMs
 
 #iterate over all VMs
 vmsCount=${#vmNamesArray[@]}
 for (( i=0;i<$vmsCount;i++)); do
    vmWorkflow ${vmNamesArray[${i}]}
 done

}

main
log "Finished backup process at `date`"
log "END"
log ""

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Samstag, 2. Oktober 2010

Virtualbox Backup Skript